They allegedly struck him in the face with their hands and poured a chemical on him.
Police said one of the suspects wrapped a rope around his neck during the attack before they both ran away.
Smollett was able to make it to Northwestern Memorial Hospital, where he was listed in good condition.
Smollett plays Jamal Lyon on “Empire.” He has been on the show since 2015.
Area Central detectives are investigating the incident as a possible hate crime.
They are looking for any video that may have recorded what happened, seeking witnesses and working to establish a timeline of events.
Anyone who has information pertinent to the investigation should call Area Central at 312-747-8382. Tips can be submitted anonymously at www.cpdtip.com.